I have a crawl space that's not vented.
What's the best way to insulate it?

Insulating a unvented crawl space is actually
much easier than a crawl space that's vented. Don't get me wrong, insulating
any crawl space is nasty work and you're about to have some memorable fun. No
sense in scratching our heads any longer - lets get started.

First you have to dress for the occasion. Put
your coveralls on, dust mask and goggles one. Take your drop light and climb
down into the crawl space. Remove any junk and debris so you have a open work
area.

Using visqueen, about a thickness of
six-mil you need to cover the ground with it. Make sure each piece overlaps at
least a foot and along the walls it should go up about 6 inches. You might
encounter some tight areas in the crawl space where there isn't much clearance.
Go ahead and grunt and swear if you want to - nobody can hear you anyway.

Now comes the fun part of insulating
unvented crawl spaces. Running parallel to the floor joists are the stringer
joists. Place a unfaced insulation batt against the subfloor and staple it into
place. Continue this process with all stringer joist areas of the unvented crawl
space.

At the end of every
floor joist there is a header joist that needs to be insulated. Cut pieces of
unfaced fiberglass batts to fit every header joist area snuggly. Continue this
process around the entire perimeter of the unvented crawl space.

The sill needs to be insulated. The
easiest way to do this is to use furring strips and nail the batts to the edge
of the sill plate. Make your cuts so the insulation drapes down the wall about
two feet into the crawl space. You should use 2X4's or 2X6's to secure the
insulation when it's close to the ground.

Next take a look at your work and fill any gaps with
scrap insulation. Like I said, insulating unvented crawl spaces is disgusting
work. Hopefully you didn't get any insulation inside of your shirt. If you did
you might find yourself sleeping on the couch tonight after your wife kicks you
out of bed for scratching too much.

Finally, get out of the crawl space
and insulate the access door by stapling a batt to it. Next, get out of those
filthy clothes, throw them in the washer and go jump in the shower. You deserve
it because you have just accomplished what many professional insulators consider
to be their worst nightmare.